He was reading The Isis Apocalypse, by former adviser to the US State Department on terrorism issues Will McCants. It explores the ideology of the terrorist organisation and is often used as a reference for journalists and researchers.

That seems a perfectly reasonable thing for a journalist to be reading in order to understand the background to the Manchester attack, which Bercito had been sent to cover for his employer, the Folha de São Paulo newspaper. But it was apparently enough for the border police to pull him in for questioning. His passport and press credentials were taken away, and he waited for an hour before he was interviewed. The police officers then explained exactly why Bercito had been singled out for special attention: another passenger on his flight had felt "uncomfortable" about his choice of reading matter.

To be fair, you can't really blame the Manchester border police for following up on that complaint, given the terrorist attack that had taken place in the city just 24 hours before. But it's a sad reflection of the effectiveness of the authorities' scaremongering that some members of the public feel the need to report someone because he or she was reading about ISIS. What next: reporting people to the police for watching TV reports about terrorism?

After a few questions, Bercito was allowed to continue with his journey, with the friendly warning not to read his book in public -- in case other, similarly-nervous people thought he was a terrorist -- as well as a less-friendly threat:

Mr Brecito said they then returned his passport to him, but warned that "if they wanted, they could keep him for a long time".